test: ensure symlink zips work

packages/acceptance-tests/pkg-tests-specs/sources/commands/install.test.ts

@@ -109,6 +109,33 @@ describe(`Commands`, () => {
       }),
     );
 
+    tests.testIf(
+      () => process.platform !== `win32`,
+      `it should install from zips that are symlinks`,
+      makeTemporaryEnv({
+        dependencies: {
+          [`no-deps`]: `1.0.0`,
+        },
+      }, async ({path, run, source}) => {
+        await run(`install`);
+
+        const allFiles = await xfs.readdirPromise(ppath.join(path, `.yarn/cache`));
+        const zipFiles = allFiles.filter(file => file.endsWith(`.zip`));
+
+        await xfs.mkdirPromise(ppath.join(path, `store`));
+        for (const filename of zipFiles) {
+          const zipFile = ppath.join(path, `.yarn/cache`, filename);
+          const storePath = ppath.join(path, `store`, filename);
+          await xfs.movePromise(zipFile, storePath);
+          await xfs.symlinkPromise(storePath, zipFile);
+        }
+
+        await xfs.removePromise(ppath.join(path, Filename.pnpCjs));
+
+        await run(`install`, `--immutable`);
+      }),
+    );
+
     test(
       `it should refuse to create a lockfile when using --immutable`,
       makeTemporaryEnv({

packages/acceptance-tests/pkg-tests-specs/sources/pnp.test.js

@@ -2253,4 +2253,31 @@ describe(`Plug'n'Play`, () => {
       });
     }),
   );
+
+  testIf(
+    () => process.platform !== `win32`,
+    `it can resolve files from zips that are symlinks`,
+    makeTemporaryEnv({
+      dependencies: {
+        [`no-deps`]: `1.0.0`,
+      },
+    }, async ({path, run, source}) => {
+      await run(`install`);
+
+      const allFiles = await xfs.readdirPromise(ppath.join(path, `.yarn/cache`));
+      const zipFiles = allFiles.filter(file => file.endsWith(`.zip`));
+
+      await xfs.mkdirPromise(ppath.join(path, `store`));
+      for (const filename of zipFiles) {
+        const zipFile = ppath.join(path, `.yarn/cache`, filename);
+        const storePath = ppath.join(path, `store`, filename);
+        await xfs.movePromise(zipFile, storePath);
+        await xfs.symlinkPromise(storePath, zipFile);
+      }
+
+      await expect(
+        source(`require('no-deps')`),
+      ).resolves.toEqual({name: `no-deps`, version: `1.0.0`});
+    }),
+  );
 });

packages/yarnpkg-libzip/tests/ZipOpenFS.test.ts

@@ -13,10 +13,15 @@ export const ZIP_DIR3 = ppath.join(
   npath.toPortablePath(__dirname),
   `fixtures/foo.hiddenzip` as Filename,
 );
+export const ZIP_DIR4 = ppath.join(
+  npath.toPortablePath(__dirname),
+  `fixtures/symlink.zip` as Filename,
+);
 
 export const ZIP_FILE1 = ppath.join(ZIP_DIR1, `foo.txt`);
 export const ZIP_FILE2 = ppath.join(ZIP_DIR2, `foo.txt`);
 export const ZIP_FILE3 = ppath.join(ZIP_DIR3, `foo.txt`);
+export const ZIP_FILE4 = ppath.join(ZIP_DIR4, `foo.txt`);
 
 afterEach(() => {
   jest.useRealTimers();
@@ -81,6 +86,14 @@ describe(`ZipOpenFS`, () => {
     fs.discardAndClose();
   });
 
+  it(`can read from a zip file that's a symlink`, () => {
+    const fs = new ZipOpenFS();
+
+    expect(fs.readFileSync(ZIP_FILE4, `utf8`)).toEqual(`foo\n`);
+
+    fs.discardAndClose();
+  });
+
   it(`doesn't close a ZipFS instance with open handles`, () => {
     const fs = new ZipOpenFS({maxOpenFiles: 1});
 

packages/yarnpkg-libzip/tests/fixtures/symlink.zip

@@ -0,0 +1 @@
+symlink-source.zip